It has been known that particulate matters (PM) contained in exhaust gas discharged from an internal combustion engine (e.g., a diesel engine) are collected by a dedicated filter (i.e., Diesel Particulate Filter (DPF)). Such a DPF is often disposed together with an engine at an engine compartment in a working vehicle such as a wheel loader.
In the arrangement in which both the engine and the DPF are disposed in the engine compartment, since a temperature of the engine compartment is remarkably increased, a forcible ventilation of the engine compartment is desired. Patent Literatures 1 and 2 propose a ventilation structure for ventilating the engine compartment using a cooling fan in a heat exchanger compartment. In the structures of Patent Literatures 1 and 2, the engine compartment intercommunicates by a hose with a fan shroud in which the cooling fan is housed and air in the engine compartment is sucked out by rotation of the cooling fan.
With such a structure, the engine compartment can be ventilated to inhibit an increase in the temperature of the engine compartment. Moreover, since this structure does not include a cooling-air intake hole with a large opening-area in the engine compartment for inhibiting the increase in the temperature by sucking a large volume of cooling air through the intake hole, noise to the environment can also be inhibited.